Thanks, I'm no expert on this mind you, but living on the coast I've learned what works and what doesn't around the house. Well... that and my job has taught me a few things. I usually can't contribute much on the forum, in contrast to what I gain, so when I can, I try to offer the best of what I know. Sometimes, I just show my ignorance
Without looking at the MSDS or Technical Data sheet it's hard to say if the Hammerite is a kissing cousin or not with POR 15. They do share the same thinner though. The POR 15 is an Isocyanate based paint (IF
I remember correctly). You know the stuff Super glue, Gorilla glue etc. are based on. You definetly want to give it some respect as I'm sure it's a hazard to ones health.
Given that you don't have the problem yet...this might be a good time to do a pre-emptive strike. Seal
the existing paint before you do have problems. Just a thought to chew on. I'd request a data sheet from both manufacturers, salt spray test results and compare.
As I said previous, hard coat anodize would be my first choice for repair/restoration, if possible. Most larger towns or cities will have at least one vendor that can do it. I know there are vendor on the net that you could ship to and have it done also.
Another good thing about hard coating is, the inside of the tube gets treated too...not as easy to do w/ paint. Yeah, you can dunk the part in an 1201 alodine bath as a pre-treatment, but unless you were able to strip the interior paint, it's not going to be effective. Anodizing
on the other hand is a multi-step process, where the part is dunked in a series of temperature controlled tanks. The first being rather caustic.
Alodine with a good non-permeable primer and top coat would be my second choice. It's probably not going to last as long as an anodized part and in a few years will more likely need to be retreated.
Thanks for your input, and sorry if I repeated myself.